Posted
by
samzenpus
on Monday December 21, 2015 @05:29PM
from the early-warning dept.

sciencehabit writes with interesting news about a possible new avenue for earthquake prediction. Sciencemag reports: "Ask seismologists when they'll be able to predict earthquakes, and the answer is generally: sometime between the distant future and never. Although there have been some promising leads over the years, the history of earthquake forecasting is littered with false starts and pseudoscience. However, some scientists think that Earth's crust may give hints before it ruptures, in the form of electromagnetic anomalies in the ground and atmosphere that occur minutes to days before an earthquake. Now, researchers are sharing their evolving understanding of these phenomena—and how they might be used to predict deadly quakes."

That just looks like more of the same to me. You get all kinds of reports, animals acting funny, strange feelings, but there is still no recorded observation. If this were a clearly linked phenomena, it would most likely have been scientifically observed already.

Electric currents are known to travel underground. There's also the piezoelectric effect where crystals put under strain can generate electric currents and thus magnetic fields. Combine that with rock being heated under pressure then snapping due to the earthquake, then it's not to hard to imagine that magnetic field lines would be reconnecting in the way that solar flares do.

Electric currents are known to travel underground. There's also the piezoelectric effect where crystals put under strain can generate electric currents and thus magnetic fields.

Under stress, actually. And producing very high voltage electric fields. So the impedance is very high, allowing small currents through even high resistances to transfer large amounts of energy, potentially for long distances.

High impedance of the SOURCE DOES enable greater energy transfers through high impedance - including high resistance - of the channel.

In this case that takes the form of a "found" channel of fixed, and high, impedance. A high voltage, low current, source will drive far more energy through that channel than a source that is capable of delivering the same amount of energy but only at a lower voltage and higher current. Impedance is voltage over current. If it weren't for breakdown (think arcing) the higher

If this were a clearly linked phenomena, it would most likely have been scientifically observed already.

It sounds to me kind of like the situation with rogue waves. They were reported by sailors for centuries, and despite this many scientists still expressed skepticism that they actually existed until 1995 when one was recorded with instrumentation. They've since been found all over the place now that we can examine huge swaths of the oceans. Previously it was sheer luck if you were there when one spa

What exactly makes me an acolyte to Mr D? When I posted, there were no visible comments, are you just jealous of us or something?

Show me a graph of the "electrical field" for a week before, during, and a week after, and prove your position. Science doesn't work on intuition, that is mysiticism. If you feel so strongly about this, PROVE IT!

You know what, go make an account, then we can have this discussion. Until then, I will assume you are a troll and just trying to get a rise out of me. You are being intentionally ignorant and attacking, when there is no need. You are also arguing against a strawman you have created, which has none of my positions in it.

However, scientists have yet to agree on a mechanism by which the crust could create electromagnetic signals. One idea is that rocks can generate positive charges when heated or stressed in the build-up to an earthquake, says Friedemann Freund, an adjunct professor of physics at San Jose State University in California and a senior scientist at NASA’s Ames Research Center in Mountain View, California. “When you stress a rock, it turns into a battery,” Freund says. “Not an electrochemical battery that you find in your car, but a new type of semiconductor battery that produces electrons and holes.”

These “holes” are positive charges that come from molecular defects known as peroxy bonds, which occur in most crystalline rocks and involve two oxygen atoms bonded together instead of to silicon or another element. At high temperatures and pressures, peroxy bonds break, causing them to pull in an electron from a neighboring atom, and leave behind a positively charged “hole.” This creates a chain reaction of electrons flowing toward the peroxy defect, effectively creating a cloud of positive charge flowing away, potentially to the surface and beyond.

By what mechanism do they expect stresses in rocks to produce electric fields?

There is a well known mechanism called the piezoelectric effect [nanomotion.com] by which stress in a crystal produces an electrical field. Quartz, for example, is a well-known piezoelectric material...and also a component of igneous rock.

I was merely pointing out that children use insults to belittle others. That or you never progressed socially since around middle school. So, the question is, who is acting more like an autist here? You insult someone you don't even know for no apparent reason, or me for pointing out your needless insults as coming from someone who is socially still in middle school.

I knew about piezoelectric effect in high school too, wow, aren't we special together. But I don't go around throwing insults at others to

It is good to hear they were cleared. That seemed like the politician/managers faithful fallback "someone must be to blame!" I hadn't heard about the outcome of the trial yet, thanks for the information.

Even in 1975 ("Haicheng Earthquake" [wikipedia.org]), schoolchildren who had been given electrical measurement kits began to detect unusual fluctuations in ground voltage. This earthquake is one of the few that have reasonably legitimately been claimed to have been predicted on the order of days in advance, with significant population lives saved by concrete action beforehand (could be fortuitous coincidence, but they definitely saw the warning signs -- and note that this earthquake is one of the many documented where animals foretold the earthquake through unusual activity).

There have also been reports of the atmosphere turning purple/blue around the location of an impending earthquake, which is probably what led to the work here. What is new is some more consistent effort to try to detect the precursors.

My uninformed interpretation of the phenomenon is that geophysical / piezoelectric stress in the rocks induces voltages/currents in the ground, which in turn cause atmospheric electrical effects that can be detected.

As a second data point, there was a whole bunch of sensitive radio receivers sitting on top of the epicenter of the Loma Prieta quake. When the data was examined, there were clear signals prior to the earthquake. A paper was published that said something like, we are not geologists. Here's our data. Enjoy.

AFAIK, no one has gone from something happens to a system that can reliably predict earthquakes.

When I was at Stanford in the 1970s there were several promising methods associated with at least one major earthquake. They included the Russian acoustic - shear velocity ratio which was supposed to change before earthquakes due to an increase in microcracks. The Chinese had two successes with farmyard animal anomalies, but missed the most costly Chinese quake in the 20th century, the Tianjin right at the doorstep of Beijing science academies. Heliem soil anomaly increases seemed promising too. The US f